step(al,bs,tm(zk,[ctxm(xi_,u,ip,ip_al_4,ip_al_4),ctxm(xi_,sp,ip,ip_bs,ip_bs)],pri(zk,[ctxm(xi_,u,kM,kM_al,kM_al),pri(pk,[ctxm(xi_,u,kM,kM_al,kM_al)]),ctxm(xi_,dot,n_z_a,ss(xi_,in_z_a),ss(xi_,cn_z_a)),ctxm(xi_,dot,n_z_b,ss(xi_,in_z_b),ss(xi_,cn_z_b))]))).
